isCOBOL Evolve : Appendices : Library Routines : IS$SQLNUL
IS$SQLNUL
The IS$SQLNUL library routine check if a select-list item allows NULL values or not.
This routine is equivalent to the Oracle’s SQLNUL routine. If you’re transitioning from Pro*COBOL and your programs are calling SQLNUL, set iscobol.oracle.sqlcall.internal=true in the configuration, and the runtime will automatically call IS$SQLNUL instead of SQLNUL.
Syntax:
 CALL "IS$SQLNUL" USING valueType
                        typeCode
                        nullStatus
Parameters:
valueType
PIC S9(4) COMP or PIC X(n) depending on the SQLDA field
Stores the datatype code of a select-list column.
typeCode
PIC S9(4) COMP or PIC X(n) depending on the SQLDA field
Returns the address of the data buffer.
nullStatus
PIC S9(9) COMP
Returns the NULL status of the select-list column. 1 means that the
column allows NULLs; 0 means that it does not.
Examples:
Example - Find out if column is NOT NULL, and clear high-order bit.
 ...
    PERFORM HANDLE-NULLS
            VARYING i FROM 1 BY 1 UNTIL i > SQLDNUM IN SELDSC.
 ...
 HANDLE-NULLS.
    CALL "IS$SQLNUL" USING SELDVTYP(i), SELDVTYP(i), NULL-STATUS.